Xanthan gum-based hydrogel containing nanocapsules for cutaneous diphenyl diselenide delivery in melanoma therapy

Recent progress in topical and transdermal approaches for melanoma treatment

The global incidence of melanoma, the most lethal form of skin cancer, continues to escalate, emphasizing the urgent need for more effective therapeutic strategies. This review assesses the latest advancements in topical and transdermal drug delivery systems, positioning them as promising alternatives. These systems allow for the direct application of therapeutic agents to tumor sites, enhancing drug effectiveness, improving patient compliance, and reducing systemic toxicity. Specifically, innovations such as nanoparticles, microneedles, and vesicular systems are explored for their potential to optimize topical and localized drug delivery. By incorporating a graphical overview of these drug delivery vehicles, we visually underscore their roles in enhancing therapeutic outcomes across various treatment categories such as chemotherapy, immunotherapy, phototherapy, phytotherapy, and targeted therapy. This article critically evaluates recent breakthroughs, addresses the current challenges faced by researchers, and explores the future directions of topical and transdermal approaches in melanoma management. By presenting a summary of the latest research and predicting future trends, this review aims to inform ongoing developments and encourage further innovation in strategies for treating melanoma.

Recent Insights into Bioactive Dichalcogen Derivatives: From Small Molecules to Complex Materials

Organodichalcogenides have been explored due to their therapeutic properties. They have been demonstrated to be active against several diseases such as cancer, bacteria, viruses, parasites, or neurological diseases. Among the different classes of dichalcogenides, disulfide derivatives have been widely studied, and many studies cover their therapeutical use. For this reason, this review includes the latest studies of diselenides and ditellurides derivatives with biological applications. With this aim, several bioactive small molecules containing the diselenide or ditelluride bond in their structure have been discussed. Furthermore, it should be highlighted that, in recent years, there has been an increasing interest in the development of nanomaterials for drug delivery due to their therapeutic advantages. In this context, diselenide and ditelluride-containing nanocarriers have emerged as novel approaches. The information compiled in this review includes small molecules and more complex materials containing diselenide or ditelluride bonds in their structure for different therapeutical applications, which could be helpful for the further development of novel drugs for the treatment of different diseases.

Blended ƙ-carrageenan and xanthan gum hydrogel containing ketoprofen-loaded nanoemulsions: Design, characterization, and evaluation in an animal model of rheumatoid arthritis

This study reports the preparation of hydrogels (HG) made with xanthan gum (XG) and ƙ-carrageenan (KC) polysaccharides containing ketoprofen (KET)-loaded nanoemulsions (NK) and their evaluation in a rheumatoid arthritis (RA) model. The nano-based HGs exhibited nanometric-sized droplets (~ 100 nm), an acidic pH (5.10-6.83), drug content above 85%, a suitable spreadability factor, and pseudoplastic flow behavior. The most promising blend (HGCX 2:1) demonstrated sustained KET release, reaching 81.44 ± 6.11% after 5 h, and superior drug concentration in the skin layers (237.91 ± 41.0 µg/g). The formulation was selected due to its enhanced bioadhesiveness, with the HG-NK formulation showing the highest bioadhesion force and occlusion factor. RA was induced by complete Freund's adjuvant (CFA) intraplantar injection into the left hind paw of male and female Swiss mice. Treatments with HGs were applied to the animals' dorsal region for 7 days. Notably, HG-NK demonstrated remarkable efficacy, reversing mechanical sensitivity in male mice and significantly reducing thermal sensitivity in both genders. Moreover, HG-NK provided a significant reduction in paw edema (52-fold in males, 27-fold in females) and inflammatory markers, such as myeloperoxidase activity (32-fold in males, 14-fold in females) and lipid peroxidation (2.5-fold in males, twofold in females). The formulation also promoted greater permeation of KET across the skin. These findings underscore the significant reduction in inflammatory markers by the HG-NK formulation, highlighting its potent anti-inflammatory effects and potential as a promising therapeutic strategy for managing RA.

Exploring Cationic Guar Gum: Innovative Hydrogels and Films for Enhanced Wound Healing

Background/Objectives: This study developed and characterized hydrogels (HG-CGG) and films (F-CGG) based on cationic guar gum (CGG) for application in wound healing. Methods: HG-CGG (2% w/v) was prepared by gum thickening and evaluated for pH, stability, spreadability, and viscosity. F-CGG was obtained using an aqueous dispersion of CGG (6% w/v) and the solvent casting method. F-CGG was characterized for thickness, weight uniformity, morphology, mechanical properties, hydrophilicity, and swelling potential. Both formulations were evaluated for bioadhesive potential on intact and injured porcine skin, as well as antioxidant activity. F-CGG was further studied for biocompatibility using hemolysis and cell viability assays (L929 fibroblasts), and its wound-healing potential by the scratch assay. Results: HG-CGG showed adequate viscosity and spreadability profiles for wound coverage, but its bioadhesive strength was reduced on injured skin. In contrast, F-CGG maintained consistent bioadhesive strength regardless of skin condition (6554.14 ± 540.57 dyne/cm2 on injured skin), presenting appropriate mechanical properties (flexible, transparent, thin, and resistant) and a high swelling capacity (2032 ± 211% after 6 h). F-CGG demonstrated superior antioxidant potential compared to HG-CGG (20.50 mg/mL ABTS+ radical scavenging activity), in addition to exhibiting low hemolytic potential and no cytotoxicity to fibroblasts. F-CGG promoted the proliferation of L929 cells in vitro, supporting wound healing. Conclusions: Therefore, CGG proved to be a promising material for developing formulations with properties suitable for cutaneous use. F-CGG combines bioadhesion, antioxidant activity, biocompatibility, cell proliferation, and potential wound healing, making it promising for advanced wound treatment.

Potentilla tormentilla Extract Loaded Gel: Formulation, In Vivo and In Silico Evaluation of Anti-Inflammatory Properties

The objective of the study was to develop a novel topical gel by mixing Potentilla tormentilla ethanolic extract, thermosensitive poloxamer 407, and carbomer 940 and evaluating its stability and rheological behavior. The irritation potential of the gel was evaluated in accordance with the Organization for Economic Cooperation and Development Guidelines 404. The potential anti-inflammatory effects of the developed gel were evaluated in vivo in rats using the carrageenan-induced paw edema test. Moreover, the in silico binding affinity for chlorogenic and ellagic acid, as dominant components in the extract, against cyclooxygenase (COX) 1 and 2 was also determined. Our findings suggest that the gel containing Potentilla tormentilla extract remained stable throughout the observation period, exhibited pseudoplastic behavior, and caused no irritation in rats, thus being considered safe for topical treatment. Additionally, the developed gel showed the capability to reduce rat paw edema, which highlights significant anti-inflammatory potential. In silico analysis revealed that chlorogenic and ellagic acid exhibited a reduced binding affinity against COX-1 but had a similar inhibitory effect on COX-2 as flurbiprofen, which was confirmed by molecular dynamics results. The study proposes the possible application of Potentilla tormentilla ethanolic extract gel for the alleviation of localized inflammatory diseases; however, future clinical evaluation is required.

Newly Developed Semi-Solid Formulations Containing Mellilotus officinalis Extract: Characterization, Assessment of Stability, Safety, and Anti-Inflammatory Activity

Melilotus officinalis has been traditionally used as an anti-inflammatory agent; nevertheless, a comprehensive evaluation of its efficacy and safety and comparison with standard drugs are lacking. Taking into consideration concerns with current therapies, like efficacy limitations, side effects, and resistance, we aimed to develop a natural gel and cream based on Melilotus officinalis extract and explore their anti-inflammatory potential. After the chemical analysis of the extract confirmed the presence of coumarin, p-coumaric acid, gallic acid, and quercetin, formulations were prepared and subjected to physical and chemical stability evaluations over 6 months. The safety potential was tested in rats, while the anti-inflammatory activity was assessed both via in silico tests and in a rat model of inflammation. The examined formulations showed stable physical characteristics at the defined storage conditions and did not exert any sign of adverse skin reaction. The gel formulation exhibited a remarkable effect in inflammation reduction comparable with hydrocortisone. The in silico results suggest that coumarin, p-coumaric, and gallic acid bind to COX-1 and COX-2 with a lower affinity compared to diclofenac. On the other hand, quercetin demonstrated comparable inhibitory activity and stronger interaction compared to the control drug. Our results indicate that the examined formulations are stable and safe and may be promising dermal products for the alleviation of inflammatory skin conditions.

Comprehensive Biosafety Profile of Carbomer-Based Hydrogel Formulations Incorporating Phosphorus Derivatives

Determining the safety of a newly developed experimental product is a crucial condition for its medical use, especially for clinical trials. In this regard, four hydrogel-type formulations were manufactured, all of which were based on carbomer (Blank-CP940) and encapsulated with caffeine (CAF-CP940), phosphorus derivatives (phenyl phosphinic (CAF-S1-CP940) and 2-carboxyethyl phenyl phosphinic acids (CAF-S2-CP940)). The main aim of this research was to provide a comprehensive outline of the biosafety profile of the above-mentioned hydrogels. The complex in vitro screening (cell viability, cytotoxicity, morphological changes in response to exposure, and changes in nuclei morphology) on two types of healthy skin cell lines (HaCaT-human keratinocytes and JB6 Cl 41-5a-murine epidermal cells) exhibited a good biosafety profile when both cell lines were treated for 24 h with 150 μg/mL of each hydrogel. A comprehensive analysis of the hydrogel's impact on the genetic profile of HaCaT cells sustains the in vitro experiments. The biosafety profile was completed with the in vivo and in ovo assays. The outcome revealed that the developed hydrogels exerted good biocompatibility after topical application on BALB/c nude mice's skin. It also revealed a lack of toxicity after exposure to the hen's chicken embryo. Further investigations are needed, regarding the in vitro and in vivo therapeutic efficacy and safety for long-term use and potential clinical translatability.

Composite Hydrogel with Oleic Acid-Grafted Mesoporous Silica Nanoparticles for Enhanced Topical Delivery of Doxorubicin

Mesoporous silica nanoparticles (MSNs) are inorganic nanocarriers presenting versatile properties and the possibility to deliver drug molecules via different routes of application. Their modification with lipids could diminish the burst release profile for water-soluble molecules. In the case of oleic acid (OA) as a lipid component, an improvement in skin penetration can be expected. Therefore, in the present study, aminopropyl-functionalized MSNs were modified with oleic acid through carbodiimide chemistry and were subsequently incorporated into a semisolid hydrogel for dermal delivery. Doxorubicin served as a model drug. The FT-IR and XRD analysis as well as the ninhydrin reaction showed the successful preparation of the proposed nanocarrier with a uniform particle size (352-449 nm) and negative zeta potential. Transmission electron microscopy was applied to evaluate any possible changes in morphology. High encapsulation efficiency (97.6 ± 1.8%) was achieved together with a sustained release profile over 48 h. The composite hydrogels containing the OA-modified nanoparticles were characterized by excellent physiochemical properties (pH of 6.9; occlusion factor of 53.9; spreadability of factor 2.87 and viscosity of 1486 Pa·s) for dermal application. The in vitro permeation study showed 2.35 fold improvement compared with the hydrogel containing free drug. In vitro cell studies showed that loading in OA-modified nanoparticles significantly improved doxorubicin's cytotoxic effects toward epidermoid carcinoma cells (A431). All of the results suggest that the prepared composite hydrogel has potential for dermal delivery of doxorubicin in the treatment of skin cancer.

Beyond the adverse effects of the systemic route: Exploiting nanocarriers for the topical treatment of skin cancers

Skin cancer is a heterogeneous disease that can be divided into two main groups, melanoma and nonmelanoma skin cancers. Conventional therapies for skin cancer have numerous systemic side effects and a high recurrence rate. Topical treatment is an alternative approach, but drug permeability remains a challenge. Therefore, nanocarriers appear as important nanotechnology tools that reduces both the side effects and improves clinical outcomes. This is why they are attracting growing interest. In this review, scientific articles on the use of nanocarriers for the topical treatment of skin cancer were collected. Despite the promising results of the presented nanocarriers and considering that some of them are already on the market, there is an urgent need for investment in the development of manufacturing methods, as well as of suitable toxicological and regulatory evaluations, since the conventional methods currently used to develop these nanocarriers-based products are more time-consuming and expensive than conventional products.

Diphenyl Diselenide Through Reduction of Inflammation, Oxidative Injury and Caspase-3 Activation Abates Doxorubicin-Induced Neurotoxicity in Rats

Neurotoxicity associated with chemotherapy is a debilitating side effect of cancer management in humans which reportedly involves inflammatory and oxidative stress responses. Diphenyl diselenide (DPDS) is an organoselenium compound which exhibits its anti-tumoral, anti-oxidant, anti-inflammatory and anti-mutagenic effects. Nevertheless, its possible effect on chemotherapy-induced neurotoxicity is not known. Using rat model, we probed the behavioral and biochemical effects accompanying administration of antineoplastic agent doxorubicin (7.5 mg/kg) and DPDS (5 and 10 mg/kg). Anxiogenic-like behavior, motor and locomotor insufficiencies associated with doxorubicin were considerably abated by both DPDS doses with concomitant enhancement in exploratory behavior as demonstrated by reduced heat maps intensity and enhanced track plot densities. Moreover, with exception of cerebral glutathione (GSH) level, superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities, biochemical data demonstrated reversal of doxorubicin-mediated decline in cerebral and cerebellar antioxidant status indices and the increase in acetylcholinesterase (AChE) activity by both doses of DPDS. Also, cerebellar and cerebral lipid peroxidation, hydrogen peroxide as well as reactive oxygen and nitrogen species levels were considerably diminished in rats administered doxorubicin and DPDS. In addition, DPDS administration abated myeloperoxidase activity, tumour necrosis factor alpha and nitric oxide levels along with caspase-3 activity in doxorubicin-administered rats. Chemoprotection of doxorubicin-associated neurotoxicity by DPDS was further validated by histomorphometry and histochemical staining. Taken together, DPDS through offsetting of oxido-inflammatory stress and caspase-3 activation elicited neuroprotection in doxorubicin-treated rats.

Xanthan: enzymatic degradation and novel perspectives of applications

The extracellular heteropolysaccharide xanthan, synthesized by bacteria of the genus Xanthomonas, is widely used as a thickening and stabilizing agent across the food, cosmetic, and pharmaceutical sectors. Expanding the scope of its application, current efforts target the use of xanthan to develop innovative functional materials and products, such as edible films, eco-friendly oil surfactants, and biocompatible composites for tissue engineering. Xanthan-derived oligosaccharides are useful as nutritional supplements and plant defense elicitors. Development and processing of such new functional materials and products often necessitate tuning of xanthan properties through targeted structural modification. This task can be effectively carried out with the help of xanthan-specific enzymes. However, the complex molecular structure and intricate conformational behavior of xanthan create problems with its enzymatic hydrolysis or modification. This review summarizes and analyzes data concerning xanthan-degrading enzymes originating from microorganisms and microbial consortia, with a particular focus on the dependence of enzymatic activity on the structure and conformation of xanthan. Through a comparative study of xanthan-degrading pathways found within various bacterial classes, different microbial enzyme systems for xanthan utilization have been identified. The characterization of these new enzymes opens new perspectives for modifying xanthan structure and developing innovative xanthan-based applications. KEY POINTS: • The structure and conformation of xanthan affect enzymatic degradation. • Microorganisms use diverse multienzyme systems for xanthan degradation. • Xanthan-specific enzymes can be used to develop xanthan variants for novel applications.

Impact of the Preparation Method on the Formulation Properties of Allantoin Hydrogels: Evaluation Using Semi-Solid Control Diagram (SSCD) Principles

Allantoin possesses numerous beneficial properties for the skin, like anti-irritant effects, wound healing, skin hydration, and epithelization. In this paper, we investigated a suitable preparation method for an allantoin hydrogel using the Semi-Solid Control Diagram (SSCD) method and characterized its rheological and consistency behavior. To accomplish this, xanthan gum (XG) was selected as a model gelling agent. Briefly, four hydrogels were prepared, two without allantoin (coded M01 and M02) and two with allantoin (M1 and M2). Similarly, the formulations were either prepared through magnetic stirring (M01 and M1) or homogenization in a mortar (M02 and M2). The prepared hydrogels were evaluated using the SSCD for specific parameters and indexes. The Good Quality Index (GQI) shows a higher value for the formulation, M1 = 6.27, compared to M2 = 5.45. This result is also underlined by the value of M01 = 6.45, which is higher than M02 = 6.38. Considering the consistency, the formulation M01 possessed the highest spreadability, followed by M02 and then the allantoin hydrogels M1 and M2. The rheological behavior had a thixotropic pseudoplastic flow for all the formulations. The use of SSCD pictographs outlined the rheological properties that need improvement, the method that is suitable to prepare the allantoin hydrogels, and the influence of the allantoin suspended in the XG hydrogel.

Smart stimuli-responsive polysaccharide nanohydrogels for drug delivery: a review

Polysaccharides have found extensive utilization as biomaterials in drug delivery systems owing to their remarkable biocompatibility, simple functionalization, and inherent biological properties. Within the array of polysaccharide-based biomaterials, there is a growing fascination for self-assembled polysaccharide nanogels (NG) due to their ease of preparation and enhanced appeal across diverse biomedical appliances. Nanogel (or nanohydrogel), networks of nanoscale dimensions, are created by physically or chemically linking polymers together and have garnered immense interest as potential carriers for delivering drugs due to their favorable attributes. These include biocompatibility, high stability, the ability to adjust particle size, the capacity to load drugs, and their inherent potential to modify their surface to actively target specific cells or tissues via the attachment of ligands that can recognize corresponding receptors. Nanogels can be engineered to respond to specific stimuli, such as pH, temperature, light, or redox conditions, allowing controlled release of the encapsulated drugs. This intelligent targeting capability helps prevent drug accumulation in unintended tissues and reduces the potential side effects. Herein, an overview of nanogels is offered, comprising their methods of preparation and the design of stimulus-responsive nanogels that enable controlled release of drugs in response to specific stimuli.

Karaya/Gellan-Gum-Based Bilayer Films Containing 3,3'-Diindolylmethane-Loaded Nanocapsules: A Promising Alternative to Melanoma Topical Treatment

This study aimed to incorporate nanocapsules containing 3,3'-diindolylmethane (DIM) with antitumor activity into a bilayer film of karaya and gellan gums for use in topical melanoma therapy. Nanocarriers and films were prepared by interfacial deposition of the preformed polymer and solvent casting methods, respectively. Incorporating DIM into nanocapsules increased its antitumor potential against human melanoma cells (A-375) (IC50 > 24.00 µg/mL free DIM × 2.89 µg/mL nanocapsules). The films were transparent, hydrophilic (θ < 90°), had homogeneous thickness and weight, and had a DIM content of 106 µg/cm2. Radical ABTS+ scavenger assay showed that the DIM films presented promising antioxidant action. Remarkably, the films showed selective bioadhesive potential on the karaya gum side. Considering the mechanical analyses, the nanotechnology-based films presented appropriate behavior for cutaneous application and controlled DIM release profile, which could increase the residence time on the application site. Furthermore, the nanofilms were found to increase the permeation of DIM into the epidermis, where melanoma develops. Lastly, the films were non-hemolytic (hemolysis test) and non-irritant (HET-CAM assay). In summary, the combination of karaya and gellan gum in bilayer films that contain nanoencapsulated DIM has demonstrated potential in the topical treatment of melanoma and could serve as a viable option for administering DIM for cutaneous melanoma therapy.

Traversing the diverse avenues of exopolysaccharides-based nanocarriers in the management of cancer

Exopolysaccharides are unique polymers generated by living organisms such as algae, fungi and bacteria to protect them from environmental factors. After a fermentative process, these polymers are extracted from the medium culture. Exopolysaccharides have been explored for their anti-viral, anti-bacterial, anti-tumor, and immunomodulatory effects. Specifically, they have acquired massive attention in novel drug delivery strategies owing to their indispensable properties like biocompatibility, biodegradability, and lack of irritation. Exopolysaccharides such as dextran, alginate, hyaluronic acid, pullulan, xanthan gum, gellan gum, levan, curdlan, cellulose, chitosan, mauran, and schizophyllan exhibited excellent drug carrier properties. Specific exopolysaccharides, such as levan, chitosan, and curdlan, have demonstrated significant antitumor activity. Moreover, chitosan, hyaluronic acid and pullulan can be employed as targeting ligands decorated on nanoplatforms for effective active tumor targeting. This review shields light on the classification, unique characteristics, antitumor activities and nanocarrier properties of exopolysaccharides. In addition, in vitro human cell line experiments and preclinical studies associated with exopolysaccharide-based nanocarriers have also been highlighted.

New Methacrylated Biopolymer-Based Hydrogels as Localized Drug Delivery Systems in Skin Cancer Therapy

The aim of the present work was to obtain drug-loaded hydrogels based on combinations of dextran, chitosan/gelatin/xanthan, and poly (acrylamide) as a sustained and controlled release vehicle of Doxorubicin, a drug used in skin cancer therapy that is associated with severe side effects. Hydrogels for use as 3D hydrophilic networks with good manipulation characteristics were produced using methacrylated biopolymer derivatives and the methacrylate group's polymerization with synthetic monomers in the presence of a photo-initiator, under UV light stimulation (365 nm). Transformed infrared spectroscopy analysis (FT-IR) confirmed the hydrogels' network structure (natural-synthetic composition and photocrosslinking), while scanning electron microscopy (SEM) analysis confirmed the microporous morphology. The hydrogels are swellable in simulated biological fluids and the material's morphology regulates the swelling properties: the maximum swelling degree was obtained for dextran-chitosan-based hydrogels because of their higher porosity and pore distribution. The hydrogels are bioadhesive on a biological simulating membrane, and values for the force of detachment and work of adhesion are recommended for applications on skin tissue. The Doxorubicin was loaded into the hydrogels and the drug was released by diffusion for all the resulting hydrogels, with small contributions from the hydrogel networks' relaxation. Doxorubicin-loaded hydrogels are efficient on keratinocytes tumor cells, the sustained released drug interrupting the cells' division and inducing cell apoptosis; we recommend the obtained materials for the topical treatment of cutaneous squamous cell carcinoma.

Gel Formulations for Topical Treatment of Skin Cancer: A Review

Skin cancer, with all its variations, is the most common type of cancer worldwide. Chemotherapy by topical application is an attractive strategy because of the ease of application and non-invasiveness. At the same time, the delivery of antineoplastic agents through the skin is difficult because of their challenging physicochemical properties (solubility, ionization, molecular weight, melting point) and the barrier function of the stratum corneum. Various approaches have been applied in order to improve drug penetration, retention, and efficacy. This systematic review aims at identifying the most commonly used techniques for topical drug delivery by means of gel-based topical formulations in skin cancer treatment. The excipients used, the preparation approaches, and the methods characterizing gels are discussed in brief. The safety aspects are also highlighted. The combinatorial formulation of nanocarrier-loaded gels is also reviewed from the perspective of improving drug delivery characteristics. Some limitations and drawbacks in the identified strategies are also outlined and considered within the future scope of topical chemotherapy.

Development of Guar Gum Hydrogel Containing Sesamol-Loaded Nanocapsules Designed for Irritant Contact Dermatitis Treatment Induced by Croton Oil Application

Irritant contact dermatitis is usually treated with corticosteroids, which cause expressive adverse effects. Sesamol is a phenolic compound with anti-inflammatory and antioxidant properties. This study was designed to evaluate a hydrogel containing sesamol-loaded ethylcellulose nanocapsules for the treatment of irritant contact dermatitis. The nanocapsules presented a size in the nanometric range, a negative zeta potential, a sesamol content close to the theoretical value (1 mg/mL), and a 65% encapsulation efficiency. Nanoencapsulation protected sesamol against UVC-induced degradation and increased the scavenging activity assessed by ABTS and DPPH radicals. The hydrogels were prepared by thickening the nanocapsule suspensions with guar gum (2.5%). The hydrogels maintained the nanometric size of the nanocapsules and a sesamol content of approximately 1 mg/g. The HET-CAM assay classified the hydrogels as nonirritating. The in vitro release of the hydrogel containing sesamol in the nanoencapsulated form demonstrated an initial burst effect followed by a prolonged sesamol release and a lower skin permeation in comparison with the hydrogel containing free sesamol. In addition, it exhibited the best anti-inflammatory effect in the irritant contact dermatitis model induced by croton oil, reducing ear edema and inflammatory cells infiltration, similar to dexamethasone (positive control). Therefore, the hydrogel containing sesamol in the nanoencapsulated form seemed to have a therapeutic potential in treating irritant contact dermatitis.

Applications of Metallic Nanoparticles in the Skin Cancer Treatment

Skin cancer is one of leading cancers globally, divided into two major categories including melanoma and nonmelanoma. Skin cancer is a global concern with an increasing trend, hence novel therapies are essential. The local treatment strategies play a key role in skin cancer therapy. Nanoparticles (NPs) exert potential applications in medicine with huge advantages and have the ability to overcome common chemotherapy problems. Recently, NPs have been used in nanomedicine as promising drug delivery systems. They can enhance the solubility of poorly water-soluble drugs, improve pharmacokinetic properties, modify bioavailability, and reduce drug metabolism. The high-efficient, nontoxic, low-cost, and specific cancer therapy is a promising goal, which can be achieved by the development of nanotechnology. Metallic NPs (MNPs) can act as important platforms. MNPs development seeks to enhance the therapeutic efficiency of medicines through site specificity, prevention of multidrug resistance, and effective delivery of therapeutic factors. MNPs are used as potential arms in the case of cancer recognition, such as Magnetic Resonance Imaging (MRI) and colloidal mediators for magnetic hyperthermia of cancer. The applications of MNPs in the cancer treatment studies are mostly due to their potential to carry a large dose of drug, resulting in a high concentration of anticancer drugs at the target site. Therefore, off-target toxicity and suffering side effects caused by high concentration of the drug in other parts of the body are avoided. MNPs have been applied as drug carriers for the of improvement of skin cancer treatment and drug delivery. The development of MNPs improves the results of many cancer treatments. Different types of NPs, such as inorganic and organic NPs have been investigated in vitro and in vivo for the skin cancer therapy. MNPs advantages mostly include biodegradability, electrostatic charge, good biocompatibility, high drug payload, and low toxicity. However, the use of controlled-release systems stimulated by electromagnetic waves, temperature, pH, and light improves the accumulation in tumor tissues and improves therapeutic outcomes. This study (2019-2022) is aimed at reviewing applications of MNPs in the skin cancer therapy.

Microbial polysaccharides: An emerging family of natural biomaterials for cancer therapy and diagnostics

Microbial polysaccharides (MPs) offer immense diversity in structural and functional properties. They are extensively used in advance biomedical science owing to their superior biodegradability, hemocompatibility, and capability to imitate the natural extracellular matrix microenvironment. Ease in tailoring, inherent bio-activity, distinct mucoadhesiveness, ability to absorb hydrophobic drugs, and plentiful availability of MPs make them prolific green biomaterials to overcome the significant constraints of cancer chemotherapeutics. Many studies have demonstrated their application to obstruct tumor development and extend survival through immune activation, apoptosis induction, and cell cycle arrest by MPs. Synoptic investigations of MPs are compulsory to decode applied basics in recent inclinations towards cancer regimens. The current review focuses on the anticancer properties of commercially available and newly explored MPs, and outlines their direct and indirect mode of action. The review also highlights cutting-edge MPs-based drug delivery systems to augment the specificity and efficiency of available chemotherapeutics, as well as their emerging role in theranostics.

Novel Pullulan/Gellan Gum Bilayer Film as a Vehicle for Silibinin-Loaded Nanocapsules in the Topical Treatment of Atopic Dermatitis

In this study a novel gellan gum/pullulan bilayer film containing silibinin-loaded nanocapsules was developed for topical treatment of atopic dermatitis (AD). The bilayer films were produced by applying a pullulan layer on a gellan gum layer incorporated with silibinin nanocapsules by two-step solvent casting method. The bilayer formation was confirmed by microscopic analysis. In vitro studies showed that pullulan imparts bioadhesitvity for the films and the presence of nanocapsules increased their occlusion factor almost 2-fold. Besides, the nano-based film presented a slow silibinin release and high affinity for cutaneous tissue. Moreover, this film presented high scavenger capacity and non-hemolytic property. In the in vivo study, interestingly, the treatments with vehicle film attenuated the scratching behavior and the ear edema in mice induced by 2,4-dinitrochlorobenzene (DNCB). However, the nano-based film containing silibinin modulated the inflammatory and oxidative parameters in a similar or more pronounced way than silibinin solution and vehicle film, as well as than hydrocortisone, a classical treatment of AD. In conclusion, these data suggest that itself gellan gum/pullulan bilayer film might attenuate the effects induced by DNCB, acting together with silibinin-loaded nanocapsules, which protected the skin from oxidative damage, improving the therapeutic effect in this AD-model.

The use of natural gums to produce nano-based hydrogels and films for topical application

Natural gums are a source of biopolymeric materials with a wide range of applications for multiple purposes. These polysaccharides are extensively explored due to their low toxicity, gelling and thickening properties, and bioadhesive potential, which have sparked interest in researchers given their use in producing pharmaceutic dosage forms compared to synthetic agents. Hence, gums can be used as gelling and film-forming agents, which are suitable platforms for topical drug administration. Additionally, recent studies have demonstrated the possibility of obtaining nanocomposite materials formed by a polymeric matrix of gums associated with nanoscale carriers that have shown superior drug delivery performance and compatibility with multiple administration routes compared to starting components. In this sense, research on topical natural gum-based form preparation containing drug-loaded nanocarriers was detailed and discussed herein. A special focus was devoted to the advantages achieved regarding physicochemical and mechanical features, drug delivery capacity, permeability through topical barriers, and biocompatibility of the hydrogels and polymeric films.

Locust Bean Gum Nano-Based Hydrogel for Vaginal Delivery of Diphenyl Diselenide in the Treatment of Trichomoniasis: Formulation Characterization and In Vitro Biological Evaluation

Trichomoniasis is the most common nonviral sexually transmitted infection in the world, but its available therapies present low efficacy and high toxicity. Diphenyl diselenide (PhSe₂) is a pharmacologically active organic selenium compound; however, its clinical use is hindered by its lipophilicity and toxicity. Nanocarriers are an interesting approach to overcome the limitations associated with this compound. This study designed and evaluated a vaginal hydrogel containing PhSe₂-loaded Eudragit^® RS100 and coconut oil nanocapsules for the treatment of trichomoniasis. Nanocapsules presented particle sizes in the nanometric range, positive zeta potential, a compound content close to the theoretical value, and high encapsulation efficiency. The nanoencapsulation maintained the anti-Trichomonas vaginalis action of the compound while improving the scavenger action in a DPPH assay. The hydrogels were prepared by thickening nanocapsule suspensions with locust bean gum (3%). The semisolids maintained the nanometric size of the particles and the PhSe₂ content at around the initial concentration (1.0 mg/g). They also displayed non-Newtonian pseudo-plastic behavior and a highly mucoadhesive property. The chorioallantoic membrane method indicated the absence of hemorrhage, coagulation, or lysis. The compound, from both non-encapsulated and nano-based hydrogel delivery systems, remained on the surface of the bovine vaginal mucosa. Therefore, the formulations displayed the intended properties and could be a promising alternative for the treatment of trichomoniasis.

Nano-based formulations as an approach for providing a novel identity for organoselenium compounds

The organoselenium compounds belong to a class of synthetic molecules that displays a remarkable spectrum of promising pharmacological properties. Despite the huge amount of preclinical data that supports a bright outlook for organoselenium compounds, some toxicity issues and physicochemical limitations delay the development of more advanced studies. Currently, several scientific reports demonstrated that the association of nanotechnology has emerged as an alternative to improve solubility and safety issues of these molecules as well as enhance pharmacological properties. Therefore, our main objective was to address studies that reported the development and biological evaluations of nano-based formulations to synthetic organoselenium compounds incorporation by constructing an integrative literature review. The data survey was performed using the Science Direct, PubMed, Web of Science, and SCOPUS online databases, covering studies that were published from January 2011 up to October 2021. In the last decade, there has been an exponential growth in research regarding the incorporation of synthetic organoselenium compounds into distinct nanocarrier systems such as nanocapsules, nanoemulsions, micelles, and others, reinforcing that the association of such molecules and nanotechnology is a promising alliance. The reports investigated many nanosystems containing selenium organic molecules intending oral, intravenous, and cutaneous applications. Besides that, these systems were evaluated in a variety of in vitro techniques and in vivo models, concerning their pharmacological potential, biodistribution profile, and safety. In summary, the findings indicate that the production of nano-based formulations containing organoselenium compounds either improved physicochemical and biological properties or minimize toxicological issues of compounds.

Mucoadhesive gellan gum hydrogel containing diphenyl diselenide-loaded nanocapsules presents improved anti-candida action in a mouse model of vulvovaginal candidiasis

The aim of this study was to evaluate the in vitro antifungal action of a diphenyl diselenide-loaded poly(ε-caprolactone) nanocapsules suspension (NC-1) and incorporate it into a gellan gum hydrogel formulation in order to assess its in vivo efficacy in an animal model of vulvovaginal candidiasis. Nanocapsules suspensions containing the compound (NC-1 ∼ 5 mg/mL) or not (NC-B) were prepared by the interfacial deposition of preformed polymer method. To estimate in vitro antifungal effect, the broth microdilution test was applied. The results showed that NC-1 had equal or lower MIC values when compared to free compound against fifteen Candida strains. Following, the hydrogel was prepared by direct thickening of the nanocapsules suspension by gellan gum addition. The animal model of vulvovaginal candidiasis was induced by infecting female Swiss mice with Candida albicans strains. The animals were topically treated with 20 µL of hydrogels (NC-1 and free compound - 0.1 mg of diphenyl diselenide/once a day for seven days) and then the total fungal burden was assessed after the euthanasia. The results showed that the hydrogels presented pH in the acidic range, compound content close to theoretical value, homogeneous particle distribution with nanometric size, high physicochemical and microbiological stability as well as great bioadhesive property. The nano-based presented superior pharmacological action in comparison to the hydrogel containing non-encapsulated diphenyl diselenide. The results demonstrated that the nanoencapsulation maintained the effective antifungal action of diphenyl diselenide. The nano-based hydrogel formulation may be considered a promising approach against vulvovaginal candidiasis.

Pullulan film incorporated with nanocapsules improves pomegranate seed oil anti-inflammatory and antioxidant effects in the treatment of atopic dermatitis in mice

This study aimed to prepare pullulan films containing pomegranate seeds oil (PSO) based nanocapsules, and evaluate the formulation efficacy in the treatment of atopic dermatitis (AD)-like lesions induced by 2,4-dinitrochlorobenzene (DNCB). The Eudragit RS 100® nanocapsules (PSONC) were prepared by the interfacial precipitation of preformed polymer, whereas the films were produced by the solvent casting method. Pomegranate seed oil nanoemulsions (PSONE) were prepared by the spontaneous emulsification method for comparative reasons. Both nanosystems presented adequate mean diameter (248 ± 16 nm for PSONE and 181 ± 6 nm for PSONC), polydispersity index (below 0.2), zeta potential (-25.63 ± 1.1 mV for PSONE and + 43.13 ± 0.7 mV for PSONC) and pH in the acid range (6.77 ± 0.27 and 5.31 ± 0.17, PSONE and PSONC). By a pre-formulation study, sorbitol (6.5%) and PEG 400 (1.5%) were considered the most suitable plasticizers for developing pullulan films (6%) intending topical application. In general, pullulan films were classified as flexible and hydrophilic, with high occlusive properties, 57.6 ± 0.8%, 64.6 ± 0.8% for vehicle, PSONCF (pullulan film containing PSONC), respectively. All formulations (films and nanocarriers) presented no irritant potential in the chorioallantoic membrane test. In the in vivo model, the treatments with free PSO and PSONCF attenuated the skin injury as well as the mechanical hypernociceptive behavioral induced by DNCB exposure to mice. Importantly, the biochemical analyses provided evidence that only the treatment with PSONCF modulated the inflammatory and the oxidative stress parameters evaluated in this study. In conclusion, these data lead us to believe that PSONC incorporation into a pullulan film matrix improved the biological properties of the PSO in this AD-model.

Nutrition and melanoma prevention

There has been considerable research in recent years on dietary factors and/or nutritional elements that might impact melanoma risk. A wide variety of dietary compounds have been studied, but only a selected group will be discussed in this review. Many have promising in vitro evidence supporting their potential, and some have been associated with decreased melanoma risk in epidemiologic studies; however, data from randomized controlled trials in humans are lacking. Future studies may be able to clarify the potential role of dietary components in melanoma risk reduction.

Lignin, lipid, protein, hyaluronic acid, starch, cellulose, gum, pectin, alginate and chitosan-based nanomaterials for cancer nanotherapy: Challenges and opportunities

Although nanotechnology-driven drug delivery systems are relatively new, they are rapidly evolving since the nanomaterials are deployed as effective means of diagnosis and delivery of assorted therapeutic agents to targeted intracellular sites in a controlled release manner. Nanomedicine and nanoparticulate drug delivery systems are rapidly developing as they play crucial roles in the development of therapeutic strategies for various types of cancer and malignancy. Nevertheless, high costs, associated toxicity and production of complexities are some of the critical barriers for their applications. Green nanomedicines have continually been improved as one of the viable approaches towards tumor drug delivery, thus making a notable impact on which considerably affect cancer treatment. In this regard, the utilization of natural and renewable feedstocks as a starting point for the fabrication of nanosystems can considerably contribute to the development of green nanomedicines. Nanostructures and biopolymers derived from natural and biorenewable resources such as proteins, lipids, lignin, hyaluronic acid, starch, cellulose, gum, pectin, alginate, and chitosan play vital roles in the development of cancer nanotherapy, imaging and management. This review uncovers recent investigations on diverse nanoarchitectures fabricated from natural and renewable feedstocks for the controlled/sustained and targeted drug/gene delivery systems against cancers including an outlook on some of the scientific challenges and opportunities in this field. Various important natural biopolymers and nanomaterials for cancer nanotherapy are covered and the scientific challenges and opportunities in this field are reviewed.

Toxicology and pharmacology of synthetic organoselenium compounds: an update

Here, we addressed the pharmacology and toxicology of synthetic organoselenium compounds and some naturally occurring organoselenium amino acids. The use of selenium as a tool in organic synthesis and as a pharmacological agent goes back to the middle of the nineteenth and the beginning of the twentieth centuries. The rediscovery of ebselen and its investigation in clinical trials have motivated the search for new organoselenium molecules with pharmacological properties. Although ebselen and diselenides have some overlapping pharmacological properties, their molecular targets are not identical. However, they have similar anti-inflammatory and antioxidant activities, possibly, via activation of transcription factors, regulating the expression of antioxidant genes. In short, our knowledge about the pharmacological properties of simple organoselenium compounds is still elusive. However, contrary to our early expectations that they could imitate selenoproteins, organoselenium compounds seem to have non-specific modulatory activation of antioxidant pathways and specific inhibitory effects in some thiol-containing proteins. The thiol-oxidizing properties of organoselenium compounds are considered the molecular basis of their chronic toxicity; however, the acute use of organoselenium compounds as inhibitors of specific thiol-containing enzymes can be of therapeutic significance. In summary, the outcomes of the clinical trials of ebselen as a mimetic of lithium or as an inhibitor of SARS-CoV-2 proteases will be important to the field of organoselenium synthesis. The development of computational techniques that could predict rational modifications in the structure of organoselenium compounds to increase their specificity is required to construct a library of thiol-modifying agents with selectivity toward specific target proteins.

Design of Pegylated-Nanocapsules to Diphenyl Diselenide Administration: In Vitro Evidence of Hemocompatible and Selective Antiglioma Formulation

Diphenyl diselenide [(PhSe)₂] is a pleiotropic pharmacological agent, but it has low aqueous solubility. The nanoencapsulation of (PhSe)₂ allowed the preparation of an aqueous formulation as well as potentiated its in vitro antitumor effect and the effectiveness in a preclinical model of glioblastoma when administered by the intragastric route. Thus, aiming at maximizing the therapeutic potential of (PhSe)₂, the present study designed a pegylated-formulation intending to intravenous administration of the (PhSe)₂ as a new approach for glioma therapy. The poly(Ɛ-caprolactone) nanocapsules containing (PhSe)₂ were physically coated with polyethyleneglycol (PEG) using the preformed polymer interfacial deposition technique and evaluated through physicochemical, morphological, spectroscopic, and thermal characteristics. Hemocompatibility was determined by the in vitro hemolysis test and cytotoxicity assays were performed in astrocytes and glioma C6 cells (10-100 μM). The pegylated-nanocapsules had an average diameter of 218 ± 25 nm, polydispersity index of 0.164 ± 0.046, zeta potential of - 8.1 ± 1.6 mV, pH 6.0 ± 0.09, (PhSe)₂ content of 102.00 ± 3.57%, and encapsulation efficiency around 98%. Besides, the (PhSe)₂ pegylated-nanocapsules were spherical, presented absence of chemical interaction among the constituents, and showed higher thermal stability than the non-encapsulated materials. PEG-coated nanocapsules did not cause hemolytic effect while formulations without PEG induced a hemolysis rate above 10%. Moreover, pegylated-nanocapsules had superior in vitro antiglioma effect in comparison to free compound (IC₅₀: 24.10 μM and 74.83 μM, respectively). Therefore, the (PhSe)₂-loaded pegylated-nanocapsule suspensions can be considered a hemocompatible formulation for the glioma treatment by the intravenous route.